Systems and methods for frequency and bandwidth optimization with a single-wire multiswitch device

ABSTRACT

This disclosure relates to a devices and methods related to satellite information broadcasting. Example embodiments may include frequency shifting an intermediate frequency (IF) signal down-conversion from the microwave-band. As an example, down-conversion involving local oscillators may lead to frequency drift due to varying temperature and/or humidity conditions. Correcting for the frequency drift may provide an opportunity to remove or filter excess bandwidth. Further embodiments may include receiving, in a tuning request, information about a transponder type. A frequency translation module may be adjusted based, at least in part, on the transponder type related to the IF signal being input into the frequency translation module. Such frequency-shifting and transponder-specific filtering may allow Single-Wire Multiswitch (SWM) devices to provide output signals with narrower bandwidth, which may improve signal quality, cable run length, reduce power demands, etc.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a divisional of and claims priority to U.S. patentapplication Ser. No. 14/694,513, filed Apr. 23, 2015, which isincorporated herein by reference in its entirety.

BACKGROUND

Satellite broadcasting of information may involve substantialinfrastructure to deliver signals to terrestrial client devices. Forexample, a plurality of ground-based microwave transmitters may transmitinformation to a plurality of satellites along a communication uplink.The plurality of satellites may be in geostationary orbit in acorresponding plurality of orbital slots. Each satellite may retransmitthe information toward ground locations as one or more satellitetransponder signals via a radio frequency (RF) communication downlink.An outdoor unit (ODU), usually mounted to a building housing the clientdevice, may receive the one or more satellite transponder signals andconvert the carrier frequency of each transponder signal to anintermediate frequency (IF) signal. The client device may send a tuningrequest to the ODU or an intermediary device, such as a Single-WireMultiswitch (SWM). The tuning request may include a requestedtransponder. In response, the IF signal or a particular transponder fromthe IF signal may be delivered to a client device. Accordingly, a tunerof the client device may then tune to a particular center frequency ofthe IF signal or the transponder signal in order to properly receive aparticular channel.

Down-conversion from RF to an IF signal may introduce frequencyinstability. That is, due to factors such as temperature and humidity,the intermediate center frequency of the down-converted signal maydrift. Furthermore, depending on a transponder type, the transpondersignals of interest may have different transmission bandwidths. Thus, inan effort to be compatible with multiple transponder types and to allowfor frequency down-conversion drift, a SWM channel of the SWM device mayinclude a default bandwidth that is wider than the transmissionbandwidth of the desired transponder signal. The SWM device may beadjusted to attenuate or remove signals outside the transmissionbandwidth of the desired transponder. Such adjustments may improve theperformance of the SWM device by improving signal to noise, increasingthe maximum cable run length, relaxing the requirements for channeloutput power, etc.

SUMMARY

In a first aspect, a method is provided. The method includes receiving asignal that includes a first carrier frequency. The method also includescombining the signal and a local oscillator tone to produce anintermediate frequency (IF) signal. The IF signal includes an IF signalbandwidth. The IF signal includes at least one transponder signal with acorresponding transponder bandwidth. The method further includesdetermining, with a processor of a Single-Wire Multiswitch (SWM) device,an intermediate center frequency of the IF signal. The method yetfurther includes determining, with the processor of the SWM device, afrequency drift based on a comparison between the intermediate centerfrequency and an expected intermediate center frequency. The methodincludes frequency shifting the IF signal based on the frequency drift.The method also includes transmitting, from the SWM device, a tuningquery via a bi-directional communication link. The SWM device includesat least one frequency translation module configured to provide at leastone SWM channel. The method yet further includes receiving, at the SWMdevice, a tuning request from a client device via the bi-directionalcommunication link. The tuning request includes a requested transpondersignal. The method also includes causing a multiswitch of the SWM deviceto connect the IF signal to the at least one SWM channel based on thetuning request. The method yet further includes causing the at least onefrequency translation module to convert the requested transponder signalto the SWM channel. The method additionally includes adjusting a centerfrequency and a bandwidth of the SMW channel such that the centerfrequency includes the expected intermediate center frequency and suchthat the bandwidth is substantially equal to the transponder bandwidth.

In a second aspect, a method is provided. The method includes receivinga signal that includes a first carrier frequency. The method alsoincludes combining the signal and a local oscillator tone to produce anintermediate frequency (IF) signal. The IF signal includes an IF signalbandwidth. The method further includes transmitting, from a Single-WireMultiswitch (SWM) device, a tuning query via a bi-directionalcommunication link. The SWM device includes at least one frequencytranslation module configured to provide at least one SWM channel. Themethod yet further includes receiving, at the SWM device, a tuningrequest from a client device via the bi-directional communication link.The tuning request includes a requested transponder signal and anexpected bandwidth of the requested transponder signal. The method alsoincludes causing a multiswitch of the SWM device to connect the IFsignal to the at least one SWM channel based on the tuning request. Themethod additionally includes causing the at least one frequencytranslation module to convert the requested transponder signal to theSWM channel. The method further includes adjusting a bandwidth of the atleast one SWM channel based on the expected bandwidth of the requestedtransponder signal. The expected bandwidth of the requested transpondersignal is less than the IF signal bandwidth.

In a third aspect, a system is provided. The system includes an antenna,a low-noise block down-converter (LNB), and a Single-Wire Multiswitch(SWM) device. The LNB includes a local oscillator and a frequency mixer.The LNB is configured to receive a signal including a first carrierfrequency via the antenna and convert the signal to an intermediatefrequency (IF) signal using the frequency mixer by combining the signaland a local oscillator tone. The IF signal includes an IF signalbandwidth. The SWM device is communicatively coupled to the LNB. The SWMdevice includes a controller and at least one digital signal processor(DSP). The controller of the SWM device is configured to determine, withthe at least one DSP, an intermediate center frequency of the IF signaland determine, with the at least one DSP, a frequency drift based on acomparison between the intermediate center frequency and an expectedintermediate center frequency. The controller of the SWM device isadditionally configured to frequency shift the IF signal based on thefrequency drift and allocate a plurality of channel bandwidths to acorresponding plurality of frequency translation modules based at leaston the IF signal bandwidth and an operating bandwidth of a clientdevice.

Other aspects, embodiments, and implementations will become apparent tothose of ordinary skill in the art by reading the following detaileddescription, with reference where appropriate to the accompanyingdrawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A is a schematic diagram illustrating a system, according to anexample embodiment.

FIG. 1B is a schematic diagram illustrating a low-noise blockdown-converter, according to an example embodiment.

FIG. 2 is a schematic diagram illustrating a system, according to anexample embodiment.

FIG. 3 is a schematic diagram illustrating a system, according to anexample embodiment.

FIG. 4 is a schematic diagram illustrating message communications,according to an example embodiment.

FIG. 5A is a schematic diagram illustrating power spectral densitywaveforms, according to an example embodiment.

FIG. 5B is a schematic diagram illustrating power spectral densitywaveforms, according to an example embodiment.

FIG. 5C is a schematic diagram illustrating power spectral densitywaveforms, according to an example embodiment.

FIG. 6 illustrates a method, according to an example embodiment.

FIG. 7 illustrates a method, according to an example embodiment.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying figures, which form a part hereof. It should be understood,however, that the arrangements described herein are set forth asexamples only. As such, those skilled in the art will appreciate thatother arrangements and elements (e.g., machines, interfaces, functions,orders of functions, etc.) can be used instead or in addition. Further,many of the elements described herein are functional entities that maybe implemented as discrete or distributed components or in conjunctionwith other components, and in any suitable combination and location.Various functions described herein as being performed by one or moreentities may be carried out by hardware, firmware or software logic. Forinstance, various functions described herein may be carried out by aprocessor executing instructions written in any suitable programminglanguage and stored in memory.

In this description, the articles “a” or “an” are used to introduceelements of the example embodiments. The intent of using those articlesis that there is one or more of the elements. The intent of using theconjunction “or” within a described list of at least two terms is toindicate any of the listed terms or any combination of the listed terms.The use of ordinal numbers such as “first,” “second,” “third” and so onis to distinguish respective elements rather than to denote a particularorder of those elements.

I. Overview

FIG. 1A is a schematic diagram illustrating a system 100, according toan embodiment. System 100 may relate to a satellite communicationdownlink scenario. For example, one or more satellites 102 may transmita signal 104 in one or more radio frequency (RF) bands, e.g., themicrowave Ka-band (26.5-40 GHz) and/or Ku-band (12.4-18 GHz). The signal104 may additionally or alternatively include other RF bands, e.g.12.2-12.7 GHz and/or 18.3-20.2 GHz. In a scenario with two or moresatellites 102, each satellite 102 may occupy a different geostationaryorbital slot.

The signal 104 may be a media signal that may include video or audiosignals. The signal 104 may also include a television signal. Thecontent of the signal may vary based on the type of signal. For example,the content may include television programming content, program guidedata or other types of data.

In an example embodiment, the signal 104 may include a plurality ofvideo and audio channels transmitted together on a single widebandcarrier, which may be associated with a particular transponder signal.The signal 104 may include one or more transponder signals transmittedfrom a particular satellite 102. The one or more satellites 102 maytransmit the signal 104 toward terrestrial locations on the Earth, suchas an Outdoor Unit (ODU) 110. The ODU 110 may be mounted on a buildingand may include an antenna 112, at least one feed horn 114, at least onelow-noise block down-converter (LNB) 120, and a support arm 116. Theantenna 112, which may include a parabolic dish antenna, may collect anddirect the broadcast signals toward the at least one feed horn 114. Eachof the feed horns 114 may be associated with at least one LNB 120.

The feed horn 114 may be located proximate to a focus of the antenna 112and may be coupled to a waveguide 118. The waveguide 118 may be a hollowmetal pipe with a rectangular or circular cross-section. Alternativelyor additionally, the waveguide 118 may include dielectric materials. Thedimensions of the waveguide 118 may be configured so as to efficientlytransmit the radio frequency signals along its length. The RF signal inthe waveguide 118 and/or feed horn 114 may be coupled to a coaxial cableor another type of electrical connection as an input to the LNB 120.

FIG. 1B is a schematic diagram illustrating an LNB 120, according to anembodiment. The LNB 120 includes an RF amplifier 122, a mixer 124, alocal oscillator 126, a filter 128, and, optionally, anintermediate-frequency (IF) amplifier 130. The RF amplifier 122 may be alow-noise amplifier (LNA) operable to amplify the RF signal fromwaveguide 118 and/or feed horn 114. The mixer 124 may include a circuitconfigured to mix the output of the RF amplifier 122 with a signal,usually a sine wave, from the local oscillator 126. The local oscillator126 may include a dielectric resonator oscillator (DRO). The DRO mayhave a fixed oscillation frequency or a variable oscillation frequency.Other types of local oscillators are contemplated herein, such as aphase-locked loop.

The mixer 124 may be a superheterodyne mixer operable to provide signalsbased on a sum and a difference of the RF signal and the localoscillator frequency, also known as a beat frequency. In someembodiments, the mixer 124 may include multiple frequency conversionstages, e.g., by mixing the RF signal with multiple local oscillators,etc.

The output of the mixer 124 may be provided as an input to the filter128. The filter 128 may be configured to attenuate or remove portions ofthe RF signal and/or the local oscillator signal. The filter 128 may bea digital filter. Accordingly, in this situation, the output of thefilter 128 may include an intermediate frequency (IF) signal. Forexample, the output of filter 128 may include a signal with a frequencyrange of 950 MHz-1450 MHz (L-Band). Alternatively, the output of filter128 may span a different frequency range.

The output of filter 128 may be provided to the IF amplifier 130. The IFamplifier 130 may be configured to amplify signals in a predeterminedrange of frequencies. Frequency down-conversion and the subsequent IFamplification by the LNB 120 may allow the signal to be transmitted viaa wire, a coaxial cable, or a fiber optic cable, as opposed to within ahollow metal waveguide.

In an example embodiment, the LNB 120, or portions thereof, may belocated proximate to the feed horn 114 so as to minimize the length ofthe waveguide 118. For instance, the LNB 120 may be provided on thesupport arm 116. In other embodiments, the LNB 120 may be locatedelsewhere.

In some embodiments, a plurality of feed horns 114 may be provided.Furthermore, each of the plurality of feed horns 114 may have acorresponding LNB 120. Together, the plurality of feed horn/LNB pairsmay be operable to receive signals from multiple satellites ingeosynchronous earth orbit. For example, each feed horn/LNB pair may beconfigured to receive signals from a particular geosynchronoussatellites located at a particular angle with respect to the antenna112. Receiving signals from multiple satellites via a plurality of feedhorns 114 and their respective LNBs 120 may enable an increased datarate and/or enable other features, such as high-definition and/or 4Ktelevision images.

FIG. 2 is a schematic diagram illustrating a system 200, according to anembodiment. System 200 may include a Single-Wire Multiswitch (SWM orSWiM) 210. The SWM 210 may include a multiswitch 212, one or more tuningchannels 220, one or more frequency translation modules 216, a combiner230, an amplifier 250, and a SWM controller 260. The one or morefrequency translation modules 216 may include respective digital and/oranalog signal processing devices. Other types of RF frequency conversiondevices are possible.

In some embodiments, the SWM 210 may include thirteen, twenty-three, ormore tuning channels 220. Each tuning channel 220 may be operable totransmit an IF signal to an in-room device, as described below.

In an example embodiment, the SWM 210 may include an analog to digitalconverter (ADC). In such scenarios, some or all of the functions of theSWM 210 may be performed with a digital signal processing (DSP) chip orintegrated circuit. That is, the SWM 210 may convert signals from analogto digital and thereafter handle or modify the signals in a digitalfashion. Alternatively, some or all of the elements and/or functions ofSWM 210 may be performed with analog devices. In an embodiment, the LNBs120 may be fully or partially incorporated into the SWM 210.Alternatively, the LNBs 120 may be provided separately from the SWM 210.

In an example embodiment, the SWM 210 may receive a plurality of IFsignals from respective LNBs 120 as described above in reference toFIGS. 1A and 1B. The plurality of IF signals may relate to one or morefrequency-downconverted transponder signals from a plurality ofsatellites. Each transponder signal may in turn include signals relatingto a plurality of broadcast channels. Each transponder signal may have arespective transponder center frequency.

Each tuning channel 220 may be switchably coupled to any of the IFsignals from the LNBs 120 via the multiswitch 212. In an exampleembodiment, each tuning channel 220 may be communicatively coupled to aparticular IF signal based on control signals received from the SWMcontroller 260. The tuning channel 220 may be connected to theparticular IF signal via a crossbar switch associated with multiswitch212. Other ways to communicatively couple a tuning channel 220 to agiven IF input are possible.

The frequency translation module 216 may include analog and/or digitalsignal processing devices configured to adjust bandwidth of tuningchannel 220. The frequency translation module 216 may be configured toadjust other aspects of tuning channel 220, such as a center frequencyof a signal.

The tuning channels 220 may be combined via combiner 230 and thecombined signal may be amplified via amplifier 250. The amplified signalmay be transmitted to one or more set top boxes (STB), in-room devices(IRDs), or client devices via a cable and/or one or more wirelesscommunication links.

The SWM controller 260 may include a processor 262, a memory 264, and acommunication module 266. The processor 262 may be a microprocessor of acomputing device, a microcontroller, a digital signal processor (DSP),multicore processor, etc. Additionally or alternatively, the processor262 may include multiple computing devices, such as in a distributedcomputing network. Processor 262 may be used to coordinate or controltuner 216, demodulator 218, decoder 220, and any other components ofsystem 200 that may or may not be illustrated in FIG. 2.

The memory 264 may include a non-transitory computer-readable medium,for example, such as computer-readable media that stores data for shortperiods of time like solid-state memory, flash drives, register memory,processor cache, and Random Access Memory (RAM). The computer-readablemedium may also or alternatively include non-transitory media, such assecondary or persistent long-term storage, like read only memory (ROM),optical or magnetic disks, compact disc read-only memory (CD-ROM), forexample. The computer-readable medium may also be any other volatile ornon-volatile storage system. The computer-readable medium may, forexample, be considered a computer-readable storage medium, a tangiblestorage device, and/or memory distributed within a computing network.

Additionally or alternatively, memory 264 may include removable storagedevices, non-removable storage devices, or a combination thereof.Examples of removable storage and non-removable storage devices includemagnetic disk devices such as flexible disk drives and hard-disk drives(HDD), optical disk drives such as compact disk (CD) drives or digitalversatile disk (DVD) drives, solid state drives (SSD), memory cards,smart cards and tape drives to name a few. Computer storage media caninclude volatile and nonvolatile, transitory, non-transitory, removableand non-removable media implemented in any method or technology forstorage of information, such as computer-readable instructions, datastructures, program modules, or other data.

The communication module 266 may be configured to receive commands froman IRD via a wired or wireless communication link. In an exampleembodiment, the communication module 266 may be operable to receive andtransmit frequency-shift keyed (FSK) messages via the wired or wirelesscommunication link. For example, the FSK messages may be transmitted andreceived via the same cable as that providing the amplified andmodulated transponder signals to the IRD. In an embodiment, digitalsignals may be transmitted and received by the communication module 266and the IRD according to a binary FSK (BFSK) protocol. In such ascenario, the communication link may be bi-directional and may includesignals having a center frequency of 2.3 MHz. Other center frequenciesare possible for the communication link.

The SWM controller 260 may control several aspects of the SWM 210. Forexample, as described above, the SWM controller 260 may be operable tocontrol the multiswitch 212 to communicatively couple various IFinputs/transponder channels to each tuning channel 220 of the SWM 210.In such a scenario, the SWM controller 260 may receive a request from aparticular IRD via the communication module 266. The request from theparticular IRD may include a tuning request for one or more particulartransponder channels. In response, the SWM controller 260 may cause themultiswitch 212 to communicatively couple the corresponding tuningchannels 220 to the particular IF signals in an effort to provide therequested transponder channels to the particular IRD according to thetuning request.

FIG. 3 is a schematic diagram illustrating a system 300, according to anembodiment. System 300 may include an In-Room Device (IRD) 310. The IRD310 may be used for television or other media. As another example, IRD310 may include or be arranged as a landline or cellular telephone,smartphone, personal computer, laptop computer, tablet computer,personal digital assistant (PDA), portable media player, set-top box, atelevision or component of a television, or other computing device nowknown or later developed.

The IRD 310 may receive signals via a wired or wireless communicationlink from the SWM 210, as illustrated and described in reference to FIG.2. The IRD 310 may handle some or all signals from SWM 210 digitally. Assuch, the IRD 310 may include an ADC and/or a DAC. Furthermore, some orall elements of IRD 310 may be included in a DSP chip, although analogembodiments are also contemplated herein.

The IRD 310 may include at least one tuner 312, at least one demodulator314, at least one decoder 316, and at least one output driver 318.Although, a particular configuration of system 300 is illustrated, theconfiguration is merely representative of various possible embodiments.For example, although only one tuner 312, one demodulator 314, and onedecoder 316 are illustrated, multiple tuners, demodulators, or decodersmay be provided within system 300. The components described in referenceto FIG. 3 may be communicatively linked by a system bus, a network, oranother connection.

The display device 340 may include a television, a monitor, or anotherdevice configured to display images. The images may be video, graphics,text, or any variety of other visual representations. In some examples,the display device 340 may include an audio output, such as aloudspeaker, to generate sound waves from media signals received by thedisplay device 340.

Display device 340 may communicate with the output driver 318 tofacilitate communication between IRD 310 and display device 340. In someimplementations, output driver 318 may work in conjunction with agraphics processing unit (not illustrated), which can be configured tocommunicate with display device 340. Output driver 318 can communicatewith display device 340 by a high-definition multiple interface (HDMI)cable, a coaxial cable, some other wired communication link, orwirelessly.

The IRD 310 may additionally include a network interface 322 and an IRDcontroller 330. One or more input devices 350 may communicate with theIRD 310 via a user interface 320. The input devices 350 may include aremote control, a keyboard, a mouse, a trackball, a smartphone, asmartwatch, a tablet, a personal computer, a voice-activated interfaceor another type of computing device. The input devices 350 mayadditionally include hardware and software configured to provide gesturerecognition. The input devices 350 may be operable to directly orindirectly control the IRD 310, the SWM 210, the LNB 120, and/or othersystems described herein. For example, a channel guide may be providedto a user via the user interface 320 and display device 340. In such ascenario, the user may use the input device 350 to select a requestedchannel.

In an example embodiment, the input device 350 may send a message to theIRD 310 via the user interface 320 and/or the communication module 336.The message may include a requested channel. In response to receiving amessage with the requested channel, the IRD controller 330 may adjustone or more tuners 312 to provide the requested channel via the displaydevice 340. Additionally or alternatively, the IRD controller 330 maytransmit a tuning request to the SWM 210 via the communication module336 according to the FSK protocol described above. Accordingly, in sucha situation, the SWM controller 260 may adjust the multiswitch 212and/or one or more tuning channels 220 so as to provide the IRD 310 witha transponder signal corresponding to the requested channel.

The one or more input device 350 may also control one or more of thedisplay devices 340. For instance, the input device 350 may be auniversal remote configured to control various functions of the displaydevices 340 and other peripherals, e.g., CD/DVD/BD player, audio/videoreceiver, a media library, etc.

The network interface 322 may be operable to communicatively connectwith a network 260. The network interface 322 may be a WiFi, WiMax,WiMax mobile, data over cable service interface specification (DOCSIS),wireless, cellular, or other types of interfaces. Moreover, networkinterface 322 may use a variety of protocols for communicating via thenetwork 260. For instance, network interface 322 may communicate usingEthernet, a Transmission Control Protocol/Internet Protocol (TCP/IP), ahypertext transfer protocol (HTTP), or some other protocol.

The IRD controller 330 may include a processor 332, a memory 334, and acommunication module 336. Similar to the SWM controller 260, the IRDcontroller 330 may be a computing device with one or more processors332. The IRD controller 320 may be configured to control various aspectsof the IRD 310. For example, the IRD controller 320 may cause the tuner312 to tune a signal from the SWM 210 in an effort to provide apreviously requested channel via the display devices 340.

II. Example Systems

Example systems described herein may relate to any or all of system 100,system 200, and/or system 300 illustrated and described in reference toFIGS. 1A-B, 2, and 3. Changing temperature and humidity conditions maycause the process of frequency down-conversion to vary over time. Thatis, the down-converted center frequency of a given IF signal and/ortransponder signal may drift. Generally, this frequency drift has beenhandled by providing the signal with some excess bandwidth. However,using frequency shifting to compensate for the frequency drift mayremove the need to provide excess bandwidth.

Excess bandwidth has also been previously allocated to handle differenttypes of transponder signals. For instance, a Ka-band-type transpondermay transmit a transponder signal with a bandwidth of 36 MHz while aKu-band-type transponder may transmit a transponder signal with a 24 MHzbandwidth. Previously, tuning channel bandwidths had been set at leastat 36 MHz to accommodate both types of transponder signals. However, byinitially receiving the type of transponder signal to be provided by agiven tuning channel, the SWM device may be able to reduce excessbandwidth in some cases, such as when a Ku-band-type transponder signalis provided by the given tuning channel.

Thus, embodiments described herein may enable a SWM device to reduceexcess bandwidth associated with a given transponder signal.Accordingly, a desired transponder signal may be provided over longercable runs, with a higher signal to noise ratio, and/or with greaterpower over the actual transponder signal bandwidth.

FIG. 4 is a schematic diagram 400 illustrating messaging communications,according to an embodiment. As illustrated in diagram 400, thecommunication module 266 of the SWM controller 260 may be configured tocommunicate with one or more client devices via a bi-directionalcommunication link. The bi-directional communication link could be awired or wireless communication link. For instance, the bi-directionalcommunication link may include message transfer according to an FSKprotocol.

In an example embodiment, the communication module 266 of SWM controller260 may transmit a tuning query 402 as a FSK message via thebi-directional communication link. The SWM controller 260 and/or the SWMcommunication module 266 may send out such tuning queries 402 via apolling process. That is, the SWM controller 260 may poll one or moreregistered client devices for new tuning requests or other information.For instance, the SWM controller 260 may access a registration list thatincludes at least one previously-registered client device. As such, theSWM controller 260 may transmit one tuning query for eachpreviously-registered client device.

In response to the tuning query 402, a client device may attempt to senda tuning request to the SWM 210. In an example embodiment, the one ormore previously-registered IRDs 310 may respond by sending a tuningrequest 406. The tuning request 406 may include a requested transpondersignal. For example, a user may have requested a particular channel froma channel guide or by entering the channel via an input device 350 of arequesting IRD, as illustrated by channel request 404. The requestingIRD, which may be IRD 310, may access a channel look-up table thatrelates specific channels to one or more transponder signals.Accordingly, the communication module 336 of the IRD controller 330 maytransmit a tuning request 406 with the corresponding requestedtransponder to the SWM 210.

In response to receiving the tuning request 406, the SWM controller 260may be configured to cause the multiswitch 212 to connect at least oneof the IF inputs from LNB 120 to at least one previously assigned tuningchannel 220 based on the tuning request 406. For example, SWM controller260 may receive a requested transponder as included in tuning request406. The SWM controller 260 may send switching command 408, which maycause the multiswitch 212 to connect at least one of the IF inputscorresponding to the requested transponder to at least one of thepreviously assigned tuning channels 220. The SWM controller 260 mayperform other functions, such as adjusting a channel bandwidth and/or achannel center frequency via the frequency translation module 216.

The IRD 310 may send a tuning command 410 to the one or more tuners 312,which may cause the tuners 312 to tune to the requested transponder.Additionally, the IRD 310 may send a filter command 412 to the one ormore filters 312.

FIGS. 5A, 5B, and 5C are schematic diagrams that illustrate powerspectral density waveforms 500, 550, and 580, according to exampleembodiments. FIGS. 5A, 5B, and 5C may illustrate ways in which excessbandwidth may be determined and removed with filters and/or digitalsignal processing.

In some embodiments, an IF signal 510 may be visualized in terms of apower spectral density waveform 500. Namely, the IF signal 510 mayinclude a plurality of transponders that may each correspond to afrequency waveband. For instance, a user may request, via tuningrequest, a desired transponder signal 512. The desired transpondersignal 512 may have an actual transponder bandwidth 522 and a desiredtransponder center frequency 514. Furthermore, the IF signal 510 mayinclude other transponder signals, such as adjacent transponder signals536 and 538, which may in adjacent frequency bands to desiredtransponder signal 512.

In order to provide the desired transponder signal 512 to the user, theSWM tuning channel output 530 may include an output bandwidth 534 thatmay include the desired transponder signal 512 as well as at least aportion of the adjacent transponder signals 536 and 538. The SWM tuningchannel output 530 may be centered on the transponder center frequency514. The output bandwidth 534 may be substantially greater than theactual transponder bandwidth 522 due to excess bandwidth 518 and 520.Excess bandwidth 518 and 520 may be included in the SWM tuning channeloutput 530 for a number of reasons described below. However, excessbandwidth 518 and 520 in the SWM tuning channel output 530 may act todecrease signal to noise ratio, limit cable run lengths, and requiregreater signal amplification.

Due to various factors such as humidity and temperature, thedown-converted IF signal may undergo frequency drift. Namely, the centerfrequency of the IF signal may vary based on, for example, a phasedeviation between a resonant portion and an active portion of thefrequency mixer circuit. In some cases, the frequency drift may beintroduced by instabilities with the resonant frequency and/or phase ofthe local oscillator, e.g., a dielectric resonant oscillator or aphase-locked loop.

In order to compensate for such frequency instability, some SWM devicesmay add excess bandwidth 518 and 520 to ensure the desired transpondersignal 512 is completely within the output bandwidth 534, as shown inFIG. 5A.

In some embodiments, the SWM controller 260 may send an initial tuningcommand that may include an expected intermediate center frequency 558.In response, an IF signal with the expected intermediate centerfrequency 558 may be switched to a tuning channel 220 via multiswitch212, as shown in FIG. 5B. The expected intermediate center frequency 558may be determined based on an intermediate center frequency look-uptable. The intermediate center frequency look-up table may include atleast one entry that includes the expected intermediate center frequency558. The look-up table may be stored at the SWM 210 or elsewhere.Alternatively, the SWM 210 may receive the expected intermediate centerfrequency 558 from the IRD 310 or from another source.

Due to the aforementioned frequency drift, the actual IF signal 554, andcorrespondingly actual intermediate center frequency 556, may be shiftedin frequency from the expected IF signal 552.

In such a scenario, the SWM controller 260 may be configured todetermine, with a digital signal processor, the actual intermediatecenter frequency 556 of the actual IF signal 554. The determination maybe made using various known digital signal processing techniques, suchas by taking a Fourier transform of the signal to produce one or morepower spectral density waveforms, such as waveforms 550. In such ascenario, the actual intermediate center frequency 556 may be determinedbased on one or more peaks or midpoints of the actual IF signal 554and/or the desired transponder signal 512.

Furthermore, the SWM controller 260 may determine a frequency drift 560based on a comparison between the actual intermediate center frequency556 and the expected intermediate center frequency 558. For example, thecomparison may return a frequency difference between actual intermediatecenter frequency 556 and the expected intermediate center frequency 558.

The SWM controller 260 may use the frequency translation module 216 tofrequency-shift the actual IF signal 554 based on the frequency drift560. By correcting the frequency drift 560, a frequency-shifted SWMtuning channel output 570 may have a narrower output bandwidth 572 thanthe output bandwidth 534 without frequency shifting. Thereafter, the SWMcontroller 260 may allocate a plurality of channel bandwidths to acorresponding plurality of tuning channels based, for example, on thenarrower output bandwidth 572 and an operating bandwidth of a clientdevice. The operating bandwidth of the client device may include thetotal bandwidth over which the tuners of the client device may be tuned.

FIG. 5C is a schematic diagram illustrating power spectral densitywaveforms 580, according to an example embodiment. An IF signal with Kutransponders 582 may include a desired transponder signal 512, which mayhave a desired transponder center frequency 514. In some cases, anoutput bandwidth 534 may be larger than the actual desired transponderbandwidth. For example, in the case of a Ku-type transponder signal, theactual transponder bandwidth may be about 24 MHz. However, in order toaccommodate Ka-type transponder signals, the output bandwidth 534 may beabout 46 MHz or more. Thus, substantial excess bandwidth may be includedwithin the output of the SWM channel.

Embodiments herein may include adjusting the output bandwidth of atuning channel based on the type of transponder corresponding to therequested transponder signal. For example, the SWM controller 260 may beconfigured to transmit a tuning query via the bi-directionalcommunication link as described in reference to FIG. 4. Further, the SWMcontroller 260 may be configured to receive a tuning request from aclient device via the bi-directional communication link. The tuningrequest may include a requested transponder signal and an expectedbandwidth of the requested transponder signal. That is, the tuningrequest may include information about the type of transponder signalthat has been requested.

The SWM controller 260 may cause an IF signal to be communicativelycoupled to a tuning channel 220. The IF signal may include a centerfrequency of the requested transponder signal. Furthermore, the SWMcontroller 260 may adjust a frequency translation module 216 associatedwith the tuning channel 220. The adjustment of the frequency translationmodule 216 may be based on the expected bandwidth of the requestedtransponder signal. For example, the expected bandwidth of the requestedtransponder signal may be less than the IF signal bandwidth.Accordingly, the adjustment of frequency translation module 216 mayinclude filtering as much excess bandwidth as possible. Thus, thetransponder-type-specific SWM filtered channel output 590 may have afiltered output bandwidth 592 identical or substantially similar to theexpected bandwidth of the requested transponder, with very little or noexcess bandwidth. By reducing excess bandwidth, example embodimentsdescribed herein may additionally or alternatively enable tighterpacking of SWM channels within a given amount of bandwidth.

III. Example Methods

FIG. 6 and FIG. 7 illustrate method 600 and method 700, respectively,according to example embodiments. Method 600 and method 700 may includevarious blocks or steps. The blocks or steps may be carried outindividually or in combination. The blocks or steps may be carried outin any order and/or in series or in parallel. Further, blocks or stepsmay be omitted or added to method 600 and method 700.

The blocks of method 600 and/or method 700 may be carried out by system200 as illustrated and described in reference to FIG. 2, however otherelements may be used to carry out the methods, such as those in system100 and system 300 from FIGS. 1 and 3. Furthermore, blocks of method 600and/or method 700 may be carried out, at least in part, by utilizing themessaging communications as illustrated and described in reference toFIG. 4. Additionally, example embodiments may include power spectraldensity waveforms similar or identical to those illustrated anddescribed in reference to FIGS. 5A, 5B, and 5C.

As illustrated in FIG. 6, block 602 includes receiving a signal thatincludes a first carrier frequency. The signal may be signal 104 asillustrated and described in FIG. 1A. That is, the signal may be amicrowave-band signal transmitted from a geostationary satellite. Thesignal may include one or more transponder signals. The transpondersignal(s) may include information, media, television programming, etc.

Block 604 includes combining the signal and a local oscillator tone toproduce an intermediate frequency (IF) signal. The IF signal includes anIF signal bandwidth. The IF signal may be provided by an LNB, such asLNB 120 as illustrated and described in reference to FIG. 1A and FIG.1B. However, other ways to down-convert a microwave-band signal arecontemplated. The IF signal may include at least one transponder signal,each of which may, in turn, include a corresponding transponderbandwidth

Block 606 includes determining, with a processor of a Single-WireMultiswitch (SWM) device, an intermediate center frequency of the IFsignal. The SWM device may be an all-digital device. Alternatively, atleast a portion of the SWM device may handle signals in an analogfashion. The SWM device may be SWM 210, however other types of SWMdevices are contemplated herein.

Block 608 includes determining, with the processor of the SWM device, afrequency drift based on a comparison between the intermediate centerfrequency and an expected intermediate center frequency. That is, asdescribed above, frequency drift may occur in conjunction with frequencydown-conversion, for example, due to variable temperature or humidityconditions. The SWM device may be configured to determine the frequencydrift by comparing the expected intermediate center frequency (which maybe known a priori) and the actual intermediate center frequency.

The expected intermediate center frequency may be known to the SWMdevice through a look-up table. For example, the look-up table mayinclude at least one entry that includes the expected intermediatecenter frequency. Alternatively, the expected intermediate centerfrequency may be provided via the bi-directional communication link. Forexample, the client device (IRD) or another device may transmit theexpected intermediate carrier to the SWM device. Other ways of obtainingthe expected intermediate carrier are possible.

The determination of the actual intermediate center frequency of the IFsignal may include finding a peak position of a power spectral densitywaveform of the IF signal. In other words, the intermediate centerfrequency may be approximated by finding the frequency of the peak of IFsignal energy. In some embodiments, the power spectral density of the IFsignal may be produced from a Fourier transform of the IF signal. Otherways to determine the actual intermediate center frequency are possible.

Block 610 includes frequency shifting the IF signal based on thefrequency drift. In some embodiments, the SWM device may initially tuneto the expected intermediate center frequency. Subsequently, frequencyshifting the IF signal may include using a digital signal processor totune from the expected intermediate center frequency to the actualintermediate center frequency.

Block 612 includes transmitting, from the SWM device, a tuning query viaa bi-directional communication link. The SWM device includes at leastone tuner and at least one filter configured to provide at least onetuning channel.

Block 614 includes receiving, at the SWM device, a tuning request from aclient device via the bi-directional communication link. The tuningrequest includes a requested transponder signal.

Block 616 includes causing a multiswitch of the SWM device to connectthe IF signal to the at least one tuning channel based on the tuningrequest.

Block 618 includes causing the at least one tuner of the at least onetuning channel to tune to the requested transponder signal.

Block 620 includes adjusting a center filter frequency and a filterbandwidth of a frequency translation module. The center filter frequencymay be adjusted such that the center filter frequency equals theexpected intermediate center frequency. The filter bandwidth may beadjusted such that the filter bandwidth is substantially equal to thetransponder bandwidth.

In some embodiments, the filter bandwidth may be a default transponderbandwidth, such as 46 MHz, minus either a) the determined frequencydrift or b) twice the determined frequency drift. Alternatively, thefilter bandwidth may be another quantity. For example, the filterbandwidth of the at least one filter may be between 34 MHz and 38 MHz.

With respect to FIG. 7, block 702 includes receiving a signal thatincludes a first carrier frequency.

Block 704 includes combining the signal and a local oscillator tone toproduce an intermediate frequency (IF) signal. The IF signal includes anIF signal bandwidth.

Block 706 includes transmitting, from a Single-Wire Multiswitch (SWM)device, a tuning query via a bi-directional communication link. The SWMdevice includes at least one tuner and at least one filter configured toprovide at least one tuning channel.

Block 708 includes receiving, at the SWM device, a tuning request from aclient device via the bi-directional communication link. The tuningrequest includes a requested transponder signal and an expectedbandwidth of the requested transponder signal. In some embodiments, theclient device may include a look-up table. The look-up table mayinclude, for instance, at least one entry that includes the requestedtransponder signal and the expected bandwidth of the requestedtransponder signal.

As described herein, the requested transponder signals may include atleast a Ka-band transponder (36 MHz transponder bandwidth) and a Ku-bandtransponder (24 MHz transponder bandwidth). Other types of transpondersand corresponding bandwidths are possible.

Block 710 includes causing a multiswitch of the SWM device to connectthe IF signal to the at least one tuning channel based on the tuningrequest.

Block 714 includes adjusting a filter bandwidth of a frequencytranslation module based on the expected bandwidth of the requestedtransponder signal. The expected bandwidth of the requested transpondersignal is less than the IF signal bandwidth. The frequency translationmodule may subsequently filter the IF signal based on the adjustedfilter bandwidth. As an example, in the case of a requested transpondersignal that corresponds to a Ku-band-type transponder, the filtering mayform a tuning channel output with a 25 MHz bandwidth as compared to thedefault 46+ MHz bandwidth. In some cases, a reduction in outputbandwidth from the SWM device may offer longer cable runs, increasedpower on the actual desired transponder signal, and better signalquality. Alternatively or additionally, example embodiments describedherein may enable more SWM channels within a given amount of tunerbandwidth at least because frequency correction and/or filtering mayallow SWM channels to be more tightly packed.

IV. Conclusion

The particular arrangements shown in the Figures should not be viewed aslimiting. It should be understood that other embodiments may includemore or less of each element shown in a given Figure. Further, some ofthe illustrated elements may be combined or omitted. Yet further, anillustrative embodiment may include elements that are not illustrated inthe Figures.

While various examples and embodiments have been disclosed, otherexamples and embodiments will be apparent to those skilled in the art.The various disclosed examples and embodiments are for purposes ofillustration and are not intended to be limiting, with the true scopebeing indicated by the following claims.

What is claimed is:
 1. A system comprising: a low-noise blockdown-converter (LNB) comprising a local oscillator and a frequencymixer, wherein the LNB, responsive to receiving a signal comprising afirst carrier frequency, converts the signal to an intermediatefrequency (IF) signal using the frequency mixer by combining the signaland a local oscillator tone, wherein the IF signal comprises an IFsignal bandwidth; and a single-wire multiswitch (SWM) devicecommunicatively coupled to the LNB, wherein the SWM device comprises: aprocessing system including a controller and a digital signal processor(DSP); and a memory that stores executable instructions that, whenexecuted by the processing system, facilitate performance of operationscomprising: determining an intermediate center frequency of the IFsignal; determining a frequency drift based on a comparison between theintermediate center frequency and an expected intermediate centerfrequency; frequency shifting the IF signal based on the frequencydrift; and allocating a plurality of channel bandwidths to acorresponding plurality of frequency translation modules based at leaston the IF signal bandwidth and an operating bandwidth of a clientdevice.
 2. The system of claim 1, wherein the LNB comprises a dielectricresonator oscillator (DRO) and wherein the local oscillator tone isprovided by the DRO.
 3. The system of claim 1, wherein the LNB comprisesa phase-locked loop (PLL) and wherein the local oscillator tone isprovided by the PLL.
 4. The system of claim 1, wherein the determiningof the intermediate center frequency of the IF signal further comprisesaccessing an intermediate center frequency look-up table, wherein theintermediate center frequency look-up table comprises an entrycomprising the expected intermediate center frequency.
 5. The system ofclaim 1, wherein the operations further comprise: transmitting a tuningquery via a bi-directional communication link, wherein the SWM devicecomprises a frequency translator including a frequency translationmodule; receiving a tuning request from the client device via thebi-directional communication link, wherein the tuning request comprisesa requested transponder signal and an expected bandwidth of therequested transponder signal; causing a multiswitch of the SWM device toconnect the IF signal to the frequency translator based on the tuningrequest; causing the frequency translator to convert to the requestedtransponder signal to an SWM channel; and adjusting a bandwidth of theSWM channel based on the expected bandwidth of the requested transpondersignal, wherein the expected bandwidth of the requested transpondersignal is less than the IF signal bandwidth.
 6. The system of claim 5,wherein the requested transponder signal comprises one of a typeprovided by a Ku-band transponder and wherein the expected bandwidth ofthe requested transponder signal is between 22 MHz and 26 MHz.
 7. Thesystem of claim 5, wherein the requested transponder signal comprisesone of a type provided by a Ka-band type transponder and wherein theexpected bandwidth of the requested transponder signal is between 34 MHzand 38 MHz.
 8. A method comprising: receiving, by a low-noise blockdown-converter (LNB), a signal comprising a first carrier frequency,wherein the LNB comprises a local oscillator and a frequency mixer,converting the signal to an intermediate frequency (IF) signal using thefrequency mixer by combining the signal and a local oscillator tone,wherein the IF signal comprises an IF signal bandwidth; determining, bya processing system of a single-wire multiswitch (SWM) device thatincludes a controller and a DSP, an intermediate center frequency of theIF signal, wherein the SWM device is communicatively coupled to the LNB;determining, by the processing system, a frequency drift based on acomparison between the intermediate center frequency and an expectedintermediate center frequency; facilitating by the processing system, afrequency shift of the IF signal based on the frequency drift; andfacilitating, by the processing system, allocation of a plurality ofchannel bandwidths to a corresponding plurality of frequency translationmodules based at least on the IF signal bandwidth and an operatingbandwidth of a client device.
 9. The method of claim 8, wherein the LNBcomprises a dielectric resonator oscillator (DRO) and wherein the localoscillator tone is provided by the DRO.
 10. The method of claim 8,wherein the LNB comprises a phase-locked loop (PLL) and wherein thelocal oscillator tone is provided by the PLL.
 11. The method of claim 8,wherein the determining of the IF signal comprises using an intermediatecenter frequency look-up table, wherein the intermediate centerfrequency look-up table comprises an entry comprising the expectedintermediate center frequency.
 12. The method of claim 8, furthercomprising: facilitating, by the processing system, transmission of atuning query via a bi-directional communication link, wherein the SWMdevice comprises a frequency translator that includes a frequencytranslation module; detecting, by the processing system, a tuningrequest received from the client device via the bi-directionalcommunication link, wherein the tuning request comprises a requestedtransponder signal and an expected bandwidth of the requestedtransponder signal; facilitating, by the processing system, operation ofa multiswitch of the SWM device to connect the IF signal to thefrequency translator based on the tuning request; facilitating, by theprocessing system, operation of the frequency translator to convert tothe requested transponder signal to a SWM channel; and adjusting, by theprocessing system, a bandwidth of the SWM channel based on the expectedbandwidth of the requested transponder signal, wherein the expectedbandwidth of the requested transponder signal is less than the IF signalbandwidth.
 13. The method of claim 12, wherein the requested transpondersignal comprises one of a type provided by a Ku-band transponder andwherein the expected bandwidth of the requested transponder signal isbetween 22 MHz and 26 MHz.
 14. The method of claim 12, wherein therequested transponder signal comprises one of a type provided by aKa-band type transponder and wherein the expected bandwidth of therequested transponder signal is between 34 MHz and 38 MHz.
 15. Anon-transitory machine-readable storage medium, comprising executableinstructions that, when executed by a processing system of a single-wiremultiswitch (SWM) device including a processor, facilitate performanceof operations, comprising: receiving an intermediate frequency (IF)signal obtained from a low-noise block down-converter (LNB) comprising alocal oscillator and a frequency mixer, wherein the IF signal comprisesan IF signal bandwidth and is obtained by combining a first carriersignal and a local oscillator tone within the frequency mixer;determining, within the SWM device, an intermediate center frequency ofthe IF signal; determining, within the SWM device, a frequency driftbased on a comparison between the intermediate center frequency and anexpected intermediate center frequency; frequency shifting the IF signalbased on the frequency drift; and allocating a plurality of channelbandwidths to a corresponding plurality of frequency translation modulesbased at least on the IF signal bandwidth and an operating bandwidth ofa client device.
 16. The non-transitory machine-readable storage mediumof claim 15, wherein the LNB comprises a dielectric resonator oscillator(DRO) and wherein the local oscillator tone is provided by the DRO. 17.The non-transitory machine-readable storage medium of claim 15, whereinthe LNB comprises a phase-locked loop (PLL) and wherein the localoscillator tone is provided by the PLL.
 18. The non-transitorymachine-readable storage medium of claim 15, wherein the SWM devicecomprises an intermediate center frequency look-up table, wherein theintermediate center frequency look-up table comprises an entrycomprising the expected intermediate center frequency.
 19. Thenon-transitory machine-readable storage medium of claim 15, wherein theoperations further comprise: transmitting a tuning query via abi-directional communication link, wherein the SWM device comprises afrequency translator including a frequency translation module;receiving, by the SWM device, a tuning request from the client devicevia the bi-directional communication link, wherein the tuning requestcomprises a requested transponder signal and an expected bandwidth ofthe requested transponder signal; facilitating operation of amultiswitch of the SWM device to connect the IF signal to the frequencytranslator based on the tuning request; facilitating operation of thefrequency translator to convert to the requested transponder signal to aSWM channel; and adjusting a bandwidth of the SWM channel based on theexpected bandwidth of the requested transponder signal, wherein theexpected bandwidth of the requested transponder signal is less than theIF signal bandwidth.
 20. The non-transitory machine-readable storagemedium of claim 19, wherein the requested transponder signal comprisesone of a type provided by a Ku-band transponder and wherein the expectedbandwidth of the requested transponder signal is between 22 MHz and 26MHz.